Origin and Application:
Deluge is a flood. In Noah’s times, the world was full of violence and sins. So God commanded a huge flood all over the world to wipe out all mankind, except the family of Noah who were safe in the ark that God asked him to build. The flood kept coming for forty days and nights, killing every living creature on earth, hence the name “the great flood”.
Deluge can figuratively mean something that is overwhelming in numbers. An IPO deluge refers to a period when companies rush to get listed in the stock market during a booming market.